super.onDraw(canvas);
canvas.drawColor(Color.RED);
// 设置字体在画板的位置
// paint.descent() - paint.ascent() - getPaddingTop()使字体位于画板的中央
canvas.drawText(text, getPaddingLeft(),
paint.descent() - paint.ascent() - getPaddingTop(), paint);
}
// 定义一个方法，对画笔的各属性进行设置
private void initPaint() {
paint = new Paint();
paint.setColor(color);
paint.setTextSize(size);
paint.setAntiAlias(true);
paint.setStyle(Style.STROKE);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
// 计算控件的大小
// 规定一个变量type 若为1 ，计算宽的大小，若为2，计算长的大小
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// 设置所测量控件的大小
setMeasuredDimension(meaSure(widthMeasureSpec, 1),
meaSure(heightMeasureSpec, 2));
}
public int meaSure(int spec, int type) {
// 首先获取定义的类型
int mode = MeasureSpec.getMode(spec);
// 获取系统默认的大小
int whsize = MeasureSpec.getSize(spec);
switch (mode) {
// 包裹内容
case MeasureSpec.AT_MOST:
int padding = 0;
int measureText = 0;
if (type == 1) {
padding = getPaddingLeft() + getPaddingRight();
measureText = (int) paint.measureText(text);
} else {
padding = getPaddingBottom() + getPaddingTop();
measureText = (int) (paint.descent() - paint.ascent());
}
// 包裹文字宽的实际长度
whsize = padding + measureText;
break;
default:
break;
}
return whsize;
}
}
<?xml version="1.0" encoding="utf-8"?>然后就是在MainActivity.XML中进行各属性的设值了。代码如下：
<RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android”
xmlns:tools=“http://schemas.android.com/tools”
xmlns:app=“http://schemas.android.com/apk/res-auto”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
